This invention relates in general to an apparatus and method for removing tubes from a tube sheet and, in particular, to an apparatus and method which permits engagement of the tube from the tube side, rather than coaxially, to eliminate the necessity of engaging the axial end of the tube in order to remove the tube from the tube sheet as previously required.
More specifically, but without restriction to the particular use which is shown and described, this invention relates to an apparatus and method for side engagement of a tube to be removed from a tube sheet which will upon actuation continuously cycle to withdraw the tube from the tube sheet while allowing the tube to be withdrawn manually upon becoming sufficiently free.
As is known to those skilled in the art, certain types of heat exchange devices contain a plurality of heat exchange tubes which extend between or are supported by at least one tube sheet. These tube sheets comprise a support plate in which a series of holes are formed which correspond to the diameter of the tubes to be supported by the plate or tube sheet. The heat exchange tubes are then inserted into the holes in the tube sheet, and the ends of the tubes expanded such that the tubes are supported by the tube sheet, and held therein by the pressure contact between the tubes and the tube sheet.
Periodically, either to effect normal maintenance or due to the necessity of replacing one or all of the tubes used in the heat-exchange unit, tubes must be removed from the tube sheet. Since the heat-exchange unit in which the tubes are used will have to be shut down during this procedure, it is very important that the removal and replacement of the tubes be completed as quickly as possible. In order to expedite such removal and replacement, various devices have been constructed in an attempt to expeditiously remove the tubes from a tube sheet. While some of these devices, for example the tube pullers disclosed in U.S. Pat. Nos. 4,077,102 and 4,283,826 have met with some success, both of the devices disclosed in this prior art require that the pulling mechanism be positioned in axial alignment with the terminal end of a tube to be removed from the tube sheet. The present invention does not require such end-to-end axial alignment between the pulling device and the tube to be pulled from the tube sheet. The present invention permits engagement of a tube which is to be removed and/or replaced from the side, partially encircling the tube while applying an axial force to remove the tube from the tube sheet.